Trigonometric functions

Let us do some maths here!

No proofs

We include no proofs whatsoever.

Integration

As the derivative of \(\sin x\) is \(\cos x\), and that of \(\cos x\) is \(-\sin x\), we have

\[\int_{a}^{b}\cos x dx = \sin b - \sin a \int_{a}^{b}\sin x dx = \cos a - \cos b\]

Isn’t that beautiful?